


Back to the Future

by orphan_account



Category: Dexter's Laboratory
Genre: Awkward Flirting, I just like splitting things up this way, M/M, Time Travel, and updating semi frequently, pls help im gay and just want more fics of these two, sorry I write short chapters, this has no relation to the movie of the same name
Language: English
Status: In-Progress
Published: 2020-01-16
Updated: 2020-03-13
Packaged: 2021-02-27 07:47:49
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 3,669
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22283617
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: When Dexter travels to the future, he finds out that his future self is dating Mandark, his sworn enemy. Now he's confused, conflicted, and seeking help from the best wingman he knows: Himself.
Relationships: Mandark Astronomanov/Dexter
Comments: 5
Kudos: 43





	1. I'M GAY??

**Author's Note:**

> Here I am in 2020 providing you all with Dexdark content because there simply isn't enough of it.

"Hm, what to do today..." Dexter paced around his laboratory, brainstorming ideas for his next project.

"I know! Why don't I just use my time machine and see what future me is up to!" He said out loud to himself.

Dexter stepped into the time machine, setting it to 3 years in the future. He giggled in anticipation, excited to see what his 16 year old self had come up with.

When he stepped out, he gasped in wonder. The productivity of his robots had increased, there were twice the amount of inventions laying around, it was everything he'd ever dreamed of.

"Now to find future me. Perhaps we can collaborate!" Dexter was grinning from ear to ear.

He shuffled through the lab, as his little legs are unable to take larger steps. He rapidly looked back and forth, taking in the view of his future lab. It was marvelous!

Just then, he noticed movement in the corner of his eye. It was him! From the future! Dexter from the past took a moment to study his future counterpart. The first thing that he noticed was that future Dexter had grown out his hair, and no longer had the neat undercut he kept six years ago. Past Dexter watched as future him grumbled and left, only to return with a stool. So he was still short in the future... unfortunate.

Future Dexter stood on his stool, tightening a bolt on his invention. Past Dexter was about to approach him, when he was interrupted by someone else.

"Deedee get out of my laboratory!" Future Dexter yelled. So some things stayed the same.

"But whyyyy. It's not like there's anything to hide."

"This is literally my secret laboratory and you just prance around willy nilly."

"Hey! My prancing is not willy nilly!"

"Yeah yeah, whatever. Just get out of my laboratory."

"Ugh fine. You're no fun anyway."

"That's nice." Future Dexter said distractedly, waving her away and not looking up from what he was doing.

"Wow." Past Dexter whispered to himself. If only the Deedee in his time period was like this.

He was snapped out of his thoughts by the sound of soft footsteps. An eerie shadown was creeping up behind his older self. Just as he was about to intervene, his future self spun around in his chair with a smug look on his face.

"Please, Mandark. You're not sneaky."

"Maybe I wasn't trying to be sneaky." Future Mandark huffed.

Dexter from the past grit his teeth. So Mandark was here. Was he going to destroy his lab? Steal his plans? Fight him?

"You're always trying to sneak up on me. While the effort is cute, it's not working." Future Dexter chuckled.

Future Mandark blushed. "Well if you're just going to make fun of me, I'll leave."

Past Dexter stopped paying attention to the conversation in front of him. Mandark? Cute? Blushing? What is this? What happened to the future? Why isn't he trying to destroy his lab? Dexter turned away from the scene to pace back and forth behind the wall of machinery. This didn't make any sense! Mandark was his enemy! His greatest rival! His-

Dexter stopped pacing to stare at the unbelievable, his face twisting into a shocked and disturbed expression.

"Excuse me! What is going on here?" Past Dexter shouted, confused and angry. Mandark and future Dexter turned to look at him, a string of saliva still connecting their mouths.

"Is that... me?" Future Dexter looked down at his younger self from the chair. Mandark stood next to him, awkward and embarrassed.

"Who else would it be? Do I know any other boy genii that can operate a time machine?"

Future Dexter gave him a skeptic look, glancing a couple of times at Mandark and hoping past Dexter would get the hint.

"I see." Past Dexter said flatly. Mandark was the only other genius he knew.

They paused, holding eye contact, as if trying to read each other's minds.

"How did this come to be?" Past Dexter demanded. 

"The last time I went to the future it was terrible! How did this," he gestured wildly at future Dexter and Mandark. "Happen?"

"Time isn't stagnant," Future Dexter explained. "The actions taken by one in the present can, and will, greatly alter the future."

"But what- and how- who- I- I- I-" Past Dexter babbled like a broken record.

"Seriously how did I not figure out I was gay until high school?" Future Dexter started his own conversation with Mandark. "I tried to steal Deedee's boyfriend. Heck! I owned Einstein pinups! No wonder my parents weren't surprised when I came out." He chuckled.

"I'M GAY??"

"No shit sherlock."

"Language." Mandark scolded his future counterpart.

"I- I have to go." Past Dexter muttered as he made his way back over to the time machine. A bright flash of light indicated that he had gone back to his own time period.

"shall we continue where we left off?"


	2. Lab Fight!

**Summary for the Chapter:**

> Dexter comes out to Deedee. Then Mandark breaks into his lab and Dexter is left with a lot to not think about.

**Notes for the Chapter:**

> Writing while tired is fun. Editing while exhausted is not.

Dexter burst into his sister's room.

"Deedee I'm gay!" He shouted, panicked.

"Cool!"

"No, not cool!" He yelled, climbing up onto her vanity.

"Okay... so what you're just gonna not be gay?"

"I cannot escape homosexuality." He said, almost threateningly while clutching the collar of her shirt.

"Sooo... what's the plan."

"I- Don't know actually..."

"Are we gonna find you a boyfriend?!"

"We are doing no such thing!"

Deedee gasped dramatically, "do you already have a boyfriend?" 

Her face splitting grin told Dexter everything he needed to know. That under no circumstances should he tell Deedee what he saw in the future.

"No." Dexter said in the most monotone voice he could.

"Bummer." Deedee shrugged. Dexter cheered internally.

"Before I forget, don't tell mom and dad," Dexter told her. "I can't have them finding out about this."

"As in, note from the principal don't tell them, or secret lab don't tell them?"

"Secret lab don't tell them! I can't have either of them knowing at any cost!"

Dexter's paranoia got the best of him, imagining every horrible scenario that could happen if either of his parents found out that he was gay. He would make sure that the worst case scenario wouldn't happen at all costs, it would be one thing to lose his lab, but to lose his family would destroy him.

\----

'Couldn't he have picked an outfit with pants?' Dexter thought to himself, trying not to be distracted by Mandark's choice of clothing. Why would anyone choose a leotard for their evil overlord outfit?

"-and you'll have no choice but to beg for mercy!" Mandark finished his evil speech, unaware that Dexter hadn't been paying any attention.

"I don't think so!" Dexter shouted a generic response, like you do when the teacher calls on you in class when you were spacing out.

"Then we will have to fight!" Mandark yelled before approaching his rival.

Now, Dexter had always hated being short, since he couldn't reach the top shelf, or doorknobs, or the top drawer, but thanks to his growth spurt he no longer had those problems! Now the problem was to face Mandark. And since he was so much shorter than him, it was a very unfortunate situation as you can imagine.

"Bring it on!" Dexter maintained eye contact, straining his neck looking upwards.

Mandark laughed obnoxiously before blindly slapping him. Dexter did the same. It was a very inefficient method of fighting.

The obvious solution slapped him in the face. He knew judo! Or at least, 5 free lessons of it. A simple take down would be enough to overpower a toothpick like Mandark.

Grabbing his leg, Dexter placed it between his own and swung him in the opposite direction. Mandark fell to the ground. Dexter stepped over his body and held his wrists down so he couldn't attack. They were both panting, and the gears in Dexter's brain were starting to turn.

Oh no. This was very awkward.

'Don't think about it. Don't think about it!' Dexter chanted to himself internally as he waited for Mandark to make the next move.

'Has Dexter always been so... short? Cute? Strong?' Mandark thought to himself, the words overlapping in his head.  
'What no!' Mandark shook himself out of his thoughts. 'He's the enemy!'

Raising himself into a bridge position, Mandark threw Dexter off of him. Dexter kept his grip on Mandark's wrists. Mandark spun him around until Dexter's back hit the wall and Mandark had him pinned. Dexter flailed his legs in an attempt at a low kick, or at least to feel the ground underneath his feet.  
Dexter felt his face heat up in embarrassment and… something else that he wasn’t going to concentrate on. Normally fights between him and Mandark weren't so... weird. But he couldn't stop thinking about what he had seen in the future. And Mandark kept getting so close.  
Snapping out of his thoughts, he looked up to see Mandark's smug grin. From the looks of it, he was winning. A swift kick to the groin by Dexter proved otherwise.

"Computer! Eject Mandark from the laboratory." Dexter ordered.

Before he could even begin to get up, a floor tile sprung from the ground, shooting Mandark out of the lab.

‘I am not thinking about the fight. My mind is empty. My mind is empty' Dexter chanted to himself in his head, pacing back and forth through his lab to calm down.

**Notes for the Chapter:**

> Heck yeah chapter 2! I'm having a lot of fun working on this, so I hope you guys enjoy reading it!


	3. Dumb like Dexter

**Summary for the Chapter:**

> Dexter realizes he has to deal with feelings and it sucks.

**Notes for the Chapter:**

> Oh yeah, it's all coming together.

"Hiiii Dexter!" Deedee sang, barging into Dexter's laboratory uninvited.

"Deedee get out of my laboratory!"

"Whatchu working on?"

Dexter opened his mouth to speak before realizing that he had no idea what he was working on. He looked down at the bolt he was repeatedly cranking and tried to figure out what the machine was. But it was Deedee who was asking, so it was a waste of time.

“That’s not important. What’s important is that you stay out of my laboratory!”

“Aww but why?” Deedee asked, swinging from a suspended bar on one of his machines.

“Because I have some very important thinking to do that’s why.” He explained, pulling her down and forcefully guiding her to the door.

After the door slammed shut, Dexter was alone with his thoughts.

“Arg! Stupid future, stupid time machine. Now I can’t even think straight!” Dexter groaned, laying his head on the lab table.

“How am I going to solve this problem? I’m the genius and even I don’t know what to do…” he trailed off, letting his words sink in.

“Wait that’s it! I’ll just travel back to the future and figure out how this all happened!”

He took off to his time machine without a second thought. Using the time he’d already had set, he pushed the button to activate the machine. With a single sigh, he walked into the future.

\----

"Back already, eh?" Future Dexter swiveled his chair around to face his past self

"Unfortunately." Past Dexter grumbled, refusing to look at his future counterpart's undoubtedly smug expression, and instead opting to study his boots.  
"I just need to knoow" he whined.

"Sit.” Future Dexter patted the stool next to him.

Past Dexter climbed up on the stool, wiggling his legs a bit as he pulled himself up. He swiveled around to face himself. 

“So, how did this happen and how do I make it stop happening?” He demanded.

“It seems a little too late for that, don’t you think?”

“Too late? How can it be too late? I already changed the future once can’t I do it again?”

"I'm going to keep this short by saying; you had your gay awakening, and now you have to deal with it."

"I- but- how- Mandark- and- what?" Dexter from the past babbled, holding his head in his hands.

"I know it may seem like a lot to take in now, but trust me it'll all work out."

"This is your fault." Past Dexter groaned.

"You do realize we're the same person, right?"

Past Dexter simply laid his head down on the desk in front of him with a sigh. Then he remembered that that's against lab safety protocol, and brought himself back up to look at his future counterpart.

"Why Mandark? Why not, oh I don't know, literally any other guy?"

"Mandark is smart, and tall, and we've known each other for so long, and-"

"Alright, I'm going to stop you right there. So this isn't some product of brainwashing?"

"If Mandark did have the ability to brainwash anyone into liking him, do you think he'd choose you?"

Past Dexter paused. "No." Saying that surprisingly hurt. Logically he knew that Mandark would choose Deedee over him any day, but there was still some weird part of him that wanted Mandark to like him back.

"This is just so… sudden and confusing. I want to go back in time and make sure this doesn't happen, but at the same time I want Mandark to like me. I don't know what I want anymore." Past Dexter said.

"I'll help you out here, but you need to make up your mind on what you want. Why don't you go back to your own time and sleep on it?" Future Dexter suggested.

“Sure, it’s not like I have any better ideas.” He grumbled, hopping off the stool and walking back to the time machine.


	4. Bus Boys

**Summary for the Chapter:**

> Dexter falls asleep on the bus, and Mandark starts to question what kind of relationship he has with Dexter.

**Notes for the Chapter:**

> This is later than I intended, I got sick and didn't have any extra time to write. Sorry about that...  
> Man I wish I could've had this ready for Valentines Day.

Monday morning arrived, the sun shining through the blinds and waking up everyone who was unfortunate enough to be sleeping near a window. Dexter’s head throbbed as he got up and out of bed. He stretched his arms over his head and undressed for his shower. He stood there for a good half hour, tiredly scrubbing himself with soap. His headache persisted even after he ate breakfast, brushed his teeth, and got on the bus.

Reflecting was a dangerous thing to do when one was trying to sleep, and Dexter had made the mistake of doing so. His eyes felt dry; he forcefully blinked to moisten them. He tugged on his gloves, feeling the latex against his fingertips. The idle chatter of his peers made a suitable white noise, and he was very tired. Staying awake was proving to be a chore.

“Is this seat taken?” Mandark’s obnoxious voice was audible from where Dexter was sitting. He cracked one eye open to watch Mandark get shoved into the other seat. Teenagers are the worst.  
Mandark got back up as the bus started again, making him fall back down. He continued to stumble back and forth, being tripped by other students, before making his way towards where Dexter was sitting.

“Morning Dorkster.” Mandark sneered.

“Good morning to you too Mandark.”

“I’m so going to get back at you for-”

“Just sit down and shut up. I’m not in the mood for this.” Dexter scowled up at his rival.

“Yeah yeah, move over.” Mandark pushed Dexter over to the window to make room for himself in the two person seat.

‘Great,’ Dexter thought, ‘Now I’m definitely not getting any rest.’ He silently glared daggers at Mandark.  
Mandark didn’t notice Dexter’s foul mood, as he was distracted by his own problems. He plugged his earbuds in to give the illusion that he was listening to music, when in reality he was plotting. There's no better time to plan your enemy's demise than when you're sitting next to him on your way to school. Dexter continued to glare at Mandark, who had a stupid look on his face as he stared at nothing in particular ahead of him.

Dexter was shaken out of his thoughts by Mandark’s obnoxious laughter. He was fairly certain that whatever harebrained scheme he had come up with wouldn’t work, like all the other ones before it. But just to get back at him for earlier, he gave Mandark a sharp elbow to the ribs.

"What the heck, you jerk." Mandark hissed and rubbed the spot Dexter had jabbed.

Dexter simply stuck his tongue out; he would not be bothered to give an explanation. Mandark only grumbled and went back to his plotting. Their silent arrangement would have gone on for longer if the bus didn’t jostle them around like a box of loose objects.

“Get your elbow away from my face.” Dexter growled, shoving Mandark off of him.

“Why don’t you get your face away from my elbow.” Mandark retorted, clutching the offending elbow.

“That doesn’t even make any sense!”

“You don’t make any sense!”

“I am not having this argument with you!”

“Well me neither!”

“Good!”

“Great!”

Dexter huffed, crossed his arms, and turned towards the window. There wasn’t much of a view from the bus, but it was better than awkwardly staring at Mandark or the seat in front of him.  
With how much he had been thinking about Mandark, you think he would have remembered how aggravating he was. No matter what Madark said, it would somehow manage to get on his nerves. He could be talking about the weather and Dexter would find the need to make some snarky remark. He couldn't even imagine Mandark without his signature evil grin.  
Mandark could also be oddly attractive in those calm moments when he wasn't fawning over Deedee, or planning to destroy Dexter. Like those times when he would brainstorm his own inventions, or care for his duck. Maybe even those times when he would condescendingly explain an equation to one of their classmates. And those rare times when he would genuinely laugh, the thought was enough to make Dexter melt. 

Dexter's head started to feel fuzzy, like it was filled with fluff. All of his thoughts started to slur together. His eyelids were heavy, and sleep was very tempting. His breathing became slow and rhythmic until he slipped away from consciousness.

Mandark peeked out of the corner of his eye to watch Dexter drift off to sleep. He was so vulnerable like this, an easy target for a number of plans that Mandark could think of off the top of his head. But… he looked so relaxed. Usually Dexter was very tense, his shoulders tightened and brows furrowed. It was nice to see him like this; peaceful and at ease.

'Cute' he thought. Then immediately shoved that thought away, because it shouldn't apply to Dexter. Cute was reserved for Deedee and small animals; not Dexter.

Dexter started to flop as the bus moved. Mandark scooted over to keep his body positioned between himself and the bus. Dexter's head fell on his shoulder as it rolled around, and Mandark held it in place. They looked stupid, with Mandark’s arm around his shoulder as if they were a couple or something. He scoffed, internally berating himself for even caring about his rival's well being.

'This is stupid. You're stupid. You’re growing soft.' He thought.

'No! I'm perfectly capable of being a terrifying villain, but I need my nemesis at full energy to enjoy watching his crushing defeat.' He convinced himself. Obviously, he only wanted a fair playing field when it came to a battle of wits. And giant robots.


	5. Sleep On It

**Summary for the Chapter:**

> Dexter skips class to lie down and is confronted with feelings he doesn't want to think about.

**Notes for the Chapter:**

> I would've updated this sooner, but unfortunately my laptop is broken. Hopefully it can be fixed soon,   
> Sorry this chapter is so short-

Dexter was rudely awoken by everything shifting around him. Mandark stood over him, looking at him like he was an idiot. He realized it was because the bus had stopped, and they arrived at school. This meant that he had fallen asleep. Next to Mandark. Oh boy. 

“What’re you looking at?” Dexter snapped.

“I was waiting for you to get up and off the bus.”

“I am going, have some patience.” He grumbled.

Dexter got out of the seat, shoving Mandark to the side on his way off the bus. He was still in a sort of sleepy daze that you get when you first wake up and nothing seems real yet. He trudged through the halls to his first class, feeling groggy. After sitting down outside the door, it hit him.

'Wait, I fell asleep on Mandark.'

And then;

'Mandark let me sleep on him'

He was now feeling a lot of emotions, confusion, panic, affection-

_Wait, what?_

Dexter's face was heating up. Maybe he could just go to the nurse's office and lie down for a bit to cool down. And sleep. A great plan.

\----

It turns out that mulling over your feelings on the hard surface of a school nurse's bench is no better than mulling them over in the hallway.

"Dexter, did you call home?" The nurse asked.

"No?" He answered, equally confused.

"Well, your cousin is here to see you."

'My cousin?' He thought. 'I don't have any cousins… or do I? Maybe-'

His thoughts were interrupted by someone sitting on the bench next to him.

"Hey cuz." His future self smiled down at him.

Dexter almost choked. "What are you doing here?" He whispered angrily. Although part of him was impressed that he was able to get into the school without anyone questioning him.

"Relax, I'm here to help."

"Sure you are, traitor."

"Hey, no need to get hostile.”

“You are fraternizing with the enemy!”

Future Dexter snorted. "Whatever you say, kiddo."

"Besides, it would be a waste of my time to pursue anyone romantically, especially Mandark."

"So you'd rather things stay as they are? With you holed up in your lab all the time and Mandark chasing after your sister?"

"... no."

Dexter stared at the ceiling, and was blinded by the shitty fluorescent lights. He turned to his side, away from future Dexter. He didn't want to talk about this, his feelings felt all mixed up and confusing. He had just wanted to lie down and rest but it was apparent that his future self wouldn't leave without an answer.

"I… will think about your offer. But right now you need to leave and I need to get back to class."

Future Dexter had an unidentifiable expression on his face before saying "Alright. Have a good day!" He smiled and ruffled his younger self's hair before getting up and heading out.

The nurse walked out of her office. "What a nice young man" she commented.

Dexter chuckled on his way out. Nice young man indeed.


End file.
